I think you need to do some more research about airsoft first when you don't know the basic terminology yet. If it is the latest revision of the JG 416, the springs are probably m120 equivalents. The gearbox is already metal. By metal body, I meant the lower receiver. Even the first iteration of the JG 416 was a 400 FPS weapon. The springs have always been on the higher FPS end. I don't know who you are talking about regarding the springs not being that great.

As I've said many times already, this gun should be good to go out of the box and not ever require any upgrades if it is based on the latest version of the JG 416 with VA's clear lower reciever installed on it.